Extant baleen whales (Mysticeti) uniquely use keratinous baleen for filter-feeding and lack dentition, but the fossil record clearly shows that "toothed" baleen whales first appeared in the Late Eocene. Globally, only two Eocene mysticetes have been found, and both are from the Southern Hemisphere: Mystacodon selenensis from Peru, 36.4 mega-annum (Ma) ago and Llanocetus denticrenatus from Antarctica, 34.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2024
Kelp forests are highly productive and economically important ecosystems worldwide, especially in the North Pacific Ocean. However, current hypotheses for their evolutionary origins are reliant on a scant fossil record. Here, we report fossil hapteral kelp holdfasts from western Washington State, USA, indicating that kelp has existed in the northeastern Pacific Ocean since the earliest Oligocene.
View Article and Find Full Text PDFContinued sampling of the latest Eocene to earliest Oligocene Gries Ranch Formation in Lewis County, Washington State, has yielded new heterobranch microgastropod species. Orbitestella kieli sp. nov.
View Article and Find Full Text PDFRecent and fossil global scissurellids were monographed by Geiger (2012) and additional species were recently described from Brazil (Pimenta Geiger 2015). Here, we describe an additional fossil species from shallow water strata of the late Eocene Gries Ranch Formation in Lewis County, Washington State, USA.
View Article and Find Full Text PDFA comprehensive discussion and survey is made of all North American Paleogene and Late Cretaceous pteropods, and their systematics reviewed. From the West Coast of North America pteropod fossils have been collected from 23 localities in Washington State, and from the Gulf Coastal Plain they have been found in 40 localities. We also review earlier published specimens from boreholes in the Atlantic Coastal Plain.
View Article and Find Full Text PDFThe bone-eating marine annelid Osedax consumes mainly whale bones on the deep-sea floor, but recent colonization experiments with cow bones and molecular age estimates suggesting a possible Cretaceous origin of Osedax indicate that this worm might be able grow on a wider range of substrates. The suggested Cretaceous origin was thought to imply that Osedax could colonize marine reptile or fish bones, but there is currently no evidence that Osedax consumes bones other than those of mammals. We provide the first evidence that Osedax was, and most likely still is, able to consume non-mammalian bones, namely bird bones.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
May 2010
Osedax is a recently discovered group of siboglinid annelids that consume bones on the seafloor and whose evolutionary origins have been linked with Cretaceous marine reptiles or to the post-Cretaceous rise of whales. Here we present whale bones from early Oligocene bathyal sediments exposed in Washington State, which show traces similar to those made by Osedax today. The geologic age of these trace fossils ( approximately 30 million years) coincides with the first major radiation of whales, consistent with the hypothesis of an evolutionary link between Osedax and its main food source, although older fossils should certainly be studied.
View Article and Find Full Text PDFThe evolutionary history of invertebrate communities utilizing whale carcasses and sunken wood in the deep-sea is explored using fossil evidence. Compared to modern whale-fall communities, the Eo-Oligocene examples lack those vent-type taxa that most heavily rely on sulphide produced by anaerobic breakdown of bone lipids, but are very similar in their trophic structure to contemporaneous wood-falls. This sheds doubt on the hypothesis that whale-falls were evolutionary stepping stones for taxa that now inhabit hydrothermal vents and seeps.
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